It has been hypothesized that O(2) sensing in type I cells of the carotid body and erythropoietin (EPO)-producing cells of the kidney involves protein components identical to the NADPH oxidase system responsible for the respiratory burst of phagocytes. In the present study, we evaluated O(2) sensing in mice with null mutant genotypes for two components of the phagocytic oxidase. Whole body plet...

Defects in gp91-phox, the large subunit of cytochrome b558 (b-245) give rise to X-linked chronic granulomatous disease (CGD), a rare inherited condition characterized by an extreme susceptibility to bacterial and fungal infection. In the majority of cases, the phagocytes are unable to generate any superoxide owing to complete absence of the flavocytochrome. However, a small minority of these pa...

BACKGROUND Chronic granulomatous disease (CGD) is a rare primary immunodeficiency (PID) caused by a dysfunctional respiratory burst enzyme NADPH-oxidase. The concurrence of Klinefelter's Syndrome (KS) and CGD would be extremely rare. OBJECTIVE We describe the study of a family where the youngest male child had X-linked CGD (X-CGD) while his older brother was both an X-CGD carrier and a Klinef...

The gp91phox-containing NADPH oxidase is the major source of reactive oxygen species (ROS) in the cardiovascular system and inactivation of gp91phox has been reported to blunt hypertension and cardiac hypertrophy seen in angiotensin (Ang) II-infused animals. In the current study, we sought to determine the role of gp91phox-derived ROS on cardiovascular outcomes of chronic exposure to Ang II. Th...

In HL-60 and ML-3 human myeloid cell lines, gamma-interferon (IFN-gamma) and/or tumor necrosis factor (TNF) induce synergistic accumulation of transcripts of the genes encoding the heavy chain (gp91-phox) of cytochrome b558 and the cytosolic factors p47-phox and p67-phox, components of the superoxide-generating NADPH oxidase system. The accumulation of transcripts for gp91-phox and p47-phox, as...

Genes encoding homologs of the gp91(phox) subunit of the plasma membrane NADPH oxidase complex have been identified in plants and are hypothesized to be a source of reactive oxygen species during defense responses. However, the direct involvement of the gene products in superoxide (O(2)(-)) production has yet to be shown. A novel activity gel assay based on protein fractionation in native or so...

The aim of this work was to analyze the effect of Interferon(IFN) and tumor necrosis factor(TNF) on NADPH oxidase activity and gp91-phox gene expression in human colostrum macrophages (CM), peripheral blood monocytes (PBM), and myelomonocytic THP-1 cells. We also investigated the effect of IFNon the release of TNFby these cells. Our results show that under basal culture conditions, CM release m...

Genes encoding homologs of the gp91 subunit of the plasma membrane NADPH oxidase complex have been identified in plants and are hypothesized to be a source of reactive oxygen species during defense responses. However, the direct involvement of the gene products in superoxide (O2 ) production has yet to be shown. A novel activity gel assay based on protein fractionation in native or sodium dodec...

The intracellular organism Anaplasma phagocytophilum causes human granulocytic ehrlichiosis and specifically infects and multiplies in neutrophilic granulocytes. Previous reports have suggested that, for its survival, this bacterium suppresses the neutrophil respiratory burst. To investigate the mechanism of survival, we first assessed the kinetics of A. phagocytophilum entry into neutrophils b...

Liu, John Q., Igor N. Zelko, Efua M. Erbynn, James S. K. Sham, and Rodney J. Folz. Hypoxic pulmonary hypertension: role of superoxide and NADPH oxidase (gp91). Am J Physiol Lung Cell Mol Physiol 290: L2–L10, 2006. First published August 5, 2005; doi:10.1152/ajplung.00135.2005.—Chronic exposure to low-O2 tension induces pulmonary arterial hypertension (PAH), which is characterized by vascular re...